What lift are these cams??

J

jiw

Guest
Hi all, i recieved a set of cams in the post yesterday, they have done low mileage by the look of them, they are hks 264's as stamped.

upon measuring the lobes i found the following dimensions:

base circle= 32.00mm on both exh and inlet lobes

top to bottom = 38.50mm on both exh and inlet lobes

this is telling me that the cams i have recieved are 6.5mm lift, surely this cannot be correct if they are the correct cams, normally the cams for the sr20 det are around 10.5-11mm lift, could anybody shed any light on wether these are the correct cams or tell me where i am going wrong with my measuring up, i also put the cams on vee block's and carried out a lift check with a d.t.i and this also confirmed the lift is 6.5mm, please tell me these aint a duff set of cams :roll:
 
J

jiw

Guest
bump :? could do with knowing as i intend on fitting these tomorrow and measuring up for shims :D
 
J

jiw

Guest
does anybody have a set of hks 264 cams laid about that have a known lift? maybe you could measure them :D just dont wanna fit the cams, remove them, work out the shim's, wait 6 weeks for them, fit the shims accordingly, start the car to find its poop :shock: , jeff
 
zia

zia

Active Member
what valve clearance did you use to measure lift and where did you place the d.t.i? the lift are only three types either, 10mm-11mm-12mm shim clearance is not going to be different with regards too different lift basically you setting clearance on base rather than ramp or flank of cams

zia
 
E

Edd

Guest
hks dont make 6.5mm lift cams for the sr20

do they have hks 264 stamped on the cam? im not sure if they have a aprt umber stamped on aswell..
 
J

jiw

Guest
i read a post after doing a search on this forum on how to denote lift, the method was described as follow's: measure the base circle, mine was 32mm, then measure 90 degree's to this from the nose of the lobe to the back of the base circle, mine was 38.5mm, it was then explained that you should take the greater figure away from the base circle figure this gave me the 6.5mm figure, not taking into account the valve angle and leverage of the rocker arm i was presuming i had 6.5mm of valve lift.

i have now fitted the cams and measured the clearances from the cam to the follower on all 8 lobes, these ranged from 0.16mm up to 0.22mm, now to find the specified clearances and see where i am at, and hopefully ive measured from the correct place, jeff
 
J

jiw

Guest
seems exhaust 1 and inlet 4 are in spec, the rest are 0.04mm over spec, would i get away with this or would it be like a tractor? i dont think their is much chance of dropping a rocker over a few hundredths, spoke to mike at mjp, seem's that the shims are a rarity and take six weeks if your lucky, jeff
 
S

sypher

New Member
is that the post i entered, to the best of my knoledge and what sweeny also put is how you determine lift, when in the engine the cam has a small clearence ( i know you know this but any way) between the follower/lifter. i take it the head is still on the car, it is ok well i suggest if you have a dti and stand you measure lift on the actual valve spring cap whilst turning cam(s). either set up on marks or don't fit chain " make sure all pistons are middle of stroke" to prevent valve / piston contact if you don't fit chain

are all the lobes the same measurement (all 16)

if poss post a pic of the cams in particular a close up of the lobes
 
J

jiw

Guest
Yeah all the same mate, gonna get my d.t.i from work on monday, i roughly measured the actual valve lift with a steel rule and got about 11mm ish, will accurately confirm it on monday.

anyone know whether leaving the clearences 0.04mm over spec will be really noisy? jeff
 
A

ard1ey

Guest
Its to do with the ratio of the rockers. The lift at the camlobe is 6.5mm as you measured, but because the cam doesn't act directly on the valve you have to take the rocker arm length and the pivot position into account. Sounds like you should be ok with what you measured. If you know what shim sizes you need I'd see how it sounds and if its tractor-like get the shims on order. Unless you have other transport you'll have to drive it anyway.
 
J

jiw

Guest
i know of nowhere as of yet and im still searching, i have thought of punching some small circular pieces of shim steel out at work and placing them inside of the bucket, sounds a bit shitty i know but i cannot see why it wouldnt work, as for needing the car, i move house soon so it will have to be driven no doubt about it, after all its only 0.04mm i cannot even see it making much noise, jeff
 
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